Transport of procainamide and N-acetylprocainamide from blood into the intestinal lumen and intestinal dialysis by oral activated charcoal in rats with acute renal failure.

Abstract

The characteristics of exsorption and/or excretion of procainamide and its metabolite, N-acetylprocainamide (NAPA), into the small intestinal lumen in both normal rats and rats with acute renal failure (ARF rats) induced by uranyl nitrate were investigated by an in situ single-pass perfusion technique. The exsorption of procainamide and NAPA from blood into the intestinal lumen was increased in ARF rats compared with normal rats. The mean apparent renal, biliary and intestinal clearance values of procainamide were 186, 1.83 and 73.9 ml/h/kg in normal rats, respectively, and were 2.02, 1.37 and 55.8 ml/h/kg in ARF rats respectively. Furthermore, the mean renal, biliary and intestinal clearance values of NAPA were 35.2, 19.4 and 21.1 ml/h/kg in normal rats, respectively, and were 1.12, 21.0 and 26.0 ml/h/kg in ARF rats, respectively. There was little difference in the intestinal clearance values of procainamide and NAPA between normal and ARF rats. The ratio of nonrenal clearance/total body clearance was greater in ARF rats than in normal rats. Treatment with oral activated charcoal reduced the serum NAPA levels in both normal and ARF rats, and had little effect on the serum procainamide levels in normal rats, while it reduced the serum drug levels in ARF rats. Consequently, the increase in both drugs transported into the intestinal lumen induced by renal failure may enhance the intestinal clearance of the drug by oral administration of activated charcoal.